Genotyping ofPseudomonas aeruginosasputum and stool isolates from cystic fibrosis patients: evidence for intestinal colonization and spreading into toilets

Abstract

SUMMARYThree hundred and fifty-eight stool and 131 sputum specimens from 40 cystic fibrosis (CF) patients and 100 toilet sinks were investigated for occurrence ofPseudomonas aeruginosa; 67% (21/31) of the patients with chronicP. aeruginosalung infections carried the organism repeatedly in the stool but the organism was found only once in the stools of nine uninfected patients.P. aeruginosastool carriage was correlated to highP. aeruginosanumbers in patients' sputa. Typing ofP. aeruginosawith a DNA probe showed identity of sputum and stool strains. Seven patients repeatedly carried additional stool strains, not found in the sputum, suggesting intestinal colonization. No differences were seen in the clinical state of patients withP. aeruginosa-negative stool samples and patients with positive stool samples. Toilets in households ofP. aeruginosa-infected CF patients were significantly more often contaminated withP. aeruginosa(42%) than toilets in households of non-infected CF patients (20%;P< 0·03). The study shows thatP. aeruginosa-infected CF patients may harbour the organisms also in the intestinal tract, and may spread the bacteria into toilets.